GetGravatar is a jQuery plugin that is a perfect touch for blog comment forms. It monitors an email address form input, and makes an AJAX request to load a Gravatar. (See a demo.) This would enable you to show a user’s Gravatar next to the comment form immediately after they input their email.

Get Gravatar is meant to be used with a text input. As the text changes in the input, it pings the Gravatar service to fetch the user’s avatar. Due to Gravatar’s restrictions, Gravatars must be retrieved with an MD5 hash of the user’s email. Since Javascript doesn’t have a built-in way to fetch an MD5 hash, this plugin has a PHP counterpart.

Obviously there are more creative uses for this, but either way it’s a nifty script.